Evaporator



Nov. 22, 1932. H. R. VAN DEVENTER ET AL 1,888,336

EVAPORATOR Filed Oct. 27, 1927 2 Sheets-Sheet lnuentars Harry R Van [lewn fer J. If"? G'rier HfTorryPy Patented Nov. 22, 1932 UNITED STATES PATENT OFFICE HARRY R. VAN DEVENTER. AND J. ALFRED GRIER, 0F NEW-YOB-K, T ASSIGNOBS, BY

-MESNE ASSIGNMENTS, TO FRIGIDAIR-E CORPORATION, OF DAYTON, OHIO, A. COR- PORATION OF DELAWARE EVAPORATOR Application filed October 27, 1927. Serial No. 299,001.

This invention relates to refrigerators and more particularly to evaporators used in mechanical refrigerating systems.

Hitherto, evaporating units of mechanical refrigerators have been built integral with the refrigerator structure or incorporated in a unitary housing adapted to be inserted therein. Such units are subject to severe mechanical stresses due to vibration and to the contraction and expansion of the metal under the influence of the expanding refrigerant and the relatively warmer air of the refrigerator chamber. These stresses eventually give rise to serious defects in the structure, especially where the parts are soldered or riveted together, and have been known to cause leakage of the refrigerant, with untimely results.

An object of this invention is the provision of an improved evaporating or cooling unit for mechanical refrigerators.

A further object of this invention is the provision of such an improved evaporator having seamless joints.

Yet another object of this invention is the provision of improved supporting means for the evaporator.

Astill further object of this invention is the provision of an improved arrangement of the pressure and suction pipes associated with the evaporator.

These and other desirable objects and advantages will be more fully described in' the following specification and illustrated in the accompanying drawings. In order that the invention maybe fully understood, a construction is disclosed which embodies the underlying principles.

In the drawings, the same numerals refer to similar parts throughout the several views, of which: A

Fig. 1 is an end view of an evaporating unit embodying our invention mounted in a refrigerator Fig. 2 is a longitudinal View, partly in section and partly in elevation of the structure shown. in Fig. 1;

Fig. 3 is an enlarged detail view of the construction of one end of the evaporating chamber, taken on line III-III of Fig. 1;

Fig. 4 is a perspective showing of the evaporator, its supports and enclosing shroud;

Fig. 5 is an end view of an evaporating unit showing still another mounting means;

Fig. 6 is a view similar to Fig. 1, showing an adjustable support for the evaporator together with a device for holding a spare ice p Fig. 7 is a view, in end elevation, of yet another adjustable support associated with an evaporator, and

Fig. 8 is alongitudinal View, partly in section and partly in elevation of the modification shown in Fig. 2.

Referring to the drawings, there is shown a segment of a refrigerator having an outer side wall 1, end wall 2, and spaced, interior side and end walls 3 and 4, respectively. The

top of the inside of the refrigerator is designated generally by the numeral 5. Positioned within the upper portion of the refrigerator chamber is a shroud member comprising a side wall 6 and a front wall 7 As shown in Fig. 4, the shroud abuts against the top, side and back of the. refrigerator chamber 8 to .form a cooling chamber 9, and is secured thereto by any suitable means, not shown. Side wall 6 is provided centrally of its upper portion adjacent the top of the refrigerator chamber, with a cut out portion 10, whose purpose will be described hereinafter. 'The walls of the shroud coact with the adjacent walls of the refrigerator to define an open air space 11. The front wall of the shroud is provided at its lower central part with a cut out portion 12, which may have any desired configuration and whose function will be discussed later. Closure means, comprising a door 13 is provided for the cut out portion the door has been shown as depending from the lugs 15, it is obvious that the several parts may be so arranged as to permit it to swing open from either side or, from the bottom of the cut out portion.

Positioned within the shroud and spaced therefrom at all points is the cooling unit or evaporator, designated generally by the numeral 18. The evaporator is supported by a plurality of U-shaped stirrups 19 and 20. Thesestirrups are bent inwardly at the ends of the leg portions to form securing flanges 21 adapted to abut against the top of the refrigerator 5. The flanges are drilled at 22 to receive headed bolts 23 which are screwed into the top of the refrigerator or otherwise attached thereto.

The evaporator is made up of two concentric shells 24 and 25 spaced apart to form a cylindrical evaporating chamber 26. The inner shell is preformed with shouldered portions 27 and 28 at either end thereof, the shoulders being extended as at 29 and 30 to form abutting flanges having substantially the same diameter as the outer shell. It will now readily be seen that the inner shell may be slid into the outer shell and secured thereto to form the evaporating chamber above noted.

While soldering or brazing may be employed to secure a gas'-tight,.pressure joint between the flanges and the adjacent portions of the outer shell, I secure new and improved results by welding them together. This is readily accomplished by setting the assembled parts in a suitable work-holding jig and fusing the metal ofthe flanges and the outer shell together. No added metal is required as there is enough material in the shells beyond the shoulders 27 and 28 to serve the purpose of the usual filler rod. The welding 0peration may be effected by a gas flame, such through out as the oxy-acetylene flame, or the like, or by the use of any of the standard types of electric are or electric resistance seam welders.

These autogenously formed seams are absolutely gas-tight, and, when properly made and subjected to the usual annealing steps, are stronger than the metal of the cylinders themselves. This method of construction provides an integral, hollow, cylinder, defining a chamber 26, above referred to, and one in which the metal is of uniform constitution the entire structure. Any stresses set up by contraction or expansion of the parts are distributed equally throughout the structure, and opening up of seams due" to difierencesin the rates of expansion and contraction of like metallic parts joined by a dissimilar metal are done away with. An added advantage resides in the fact that the differences in cost between autogenous welding, where no filler metal is required, and soldering or brazing, is merely nominal, and may even on large scale or quantity production be decidedly in favor of the welding method.

The expansion chamber is provided with a bossed inlet opening 31 and a bossed outlet opening 32. The inlet opening is welded to the outer shell centrally of its lowest point, while the outlet opening is welded to the inner shell centrally of its highest point. In fluid communication with the pressure side of a compressor, not shown,'is the inlet pipe 33.

the expansion chamber in the course of itsflow from the inlet to the outlet and that a maximum abstraction of heat will be effected.

Welded into the outlet opening of the expansion chamber is an eduction pipe 36 which is suitably connected to the suction side of the compressor engine. above referred to. The eduction pipe passes through the upper portion of the open-ended cylindrical cylinder formed by the inner shell of the expansion chamber and permits the expanded, cool gas or vapor to give up any available cold values. The pressure and suction pipes are led out of the cooling chamber through an aperture 38 in the walls of the refrigerator, and thence to the compressor, not shown. A suitable protective means or guard, 39, is provided for the pipes exteriorly of the refrigerating chamber. Added economies in operation may be effected by having the inlet and outlet pipes in heat-exchanging relation throughout their length whereby the compressed refrigerant is further cooled before being permitted to expand.

The inner shell of the evaporating chamber is provided with oppositely positioned supports, 40, 40', 41, 41 and 42, 42', for the ice drawers 43, 44 and 45. The supports may have different configurations, as shown, particularly in Fig. 1, to accommodate the number of drawers desired, and are welded to the inner surface of the inside of the inner shell of the expansion chamber. As noted hereinbefore, various welding operations are required in assembling the parts of the expansion chamber. We simplify this procedure in a great measure by welding the ice drawer supports and the outlet pipe boss onto the inner cylinder before assembling the latter with the outer cylinder. The bossed inlet may be welded onto the outer shell at any time, as desired, although we prefer to preform the various parts and assemble the units as conditions demand. It will, of course, be readily understood that instead of welding the bosses on to the shells, the latter may be fabricated with integral bossed portions, which procedure is current practice in sheet-metal working. scribed the evaporating chamber as being substantially cylindrical in shape, it will be understood that it may be oval, rectangular, polygonal or any other desired form.

hen the unit is in operation the refrigerant is pumped under pressure through the pressure pipe to the expansion valve. From here it is released into the expansion chamber through the inlet pipe. In the expansion chamber it expands adiabatically with a drop in temperature, cooling the surrounding metal, which in turn cools the air in the refrigerating chamber. The cool air surrounding the evaporator descends into the refrigerator proper through the open bottom of the shroud, and the warm air it displaces ascends and circulates through the opening in the upper central portion of the side wall of the shroud. The circulation of air around and about the evaporator is essentially at right angles to its longitudinal axis. There is rela tively little circulation through the interior of the cylinder containing the ice drawers, with the result that the cold air has ample opportunity to contact with the ice drawers and abstract heat therefrom. This air space interiorly of the cylinder is kept cool by the provision of the door in the front of the shroud, previously described. It will be readily seen that when the door is closed, both open ends of the inner chamber are subject to substantially equal air flow, tending to set up a condition of equilibrium in the center of the chamber. The door is opened only for the purpose of inserting and removing the ice drawers, as occasion demands, and is normally kept closed. Where an increased cooling effect is desired in the interior of the evaporator, it is closed, as shown in Fig. 8, by means of a suitable plate 46. This plate conforms to the shape of the evaporator and abuts against the shoulder 28, to which it is secured in any suitable manner, as by welding. An opening 41 is provided for the exit pipe from the evaporating chamber. The provision of an end closure materially in creases the refrigerating effect in the central chamber by reducing air currents therein to an absolute minimum, thereby increasing the speed of ice formation.

In place of the U-shaped stirrups previously described. we contemplate making use of a plurality of hangers to which the evaporator is directly joined. As shown, particularly in Fig. 5, we provide members 19a and 19b, bent to form securing flanges 21 as already described. The straps are welded to the outer shell of the evaporator as indicated at 50 and 51. This construction permits of marked economies in material by el minating the bottom of the stirrups. and is adapted for use in new construction where the lining up of the evaporator is readily accomplished.

here a maximum range of adjustability While we have del is desired, we make use of the construction shown in Fig. 6. This construction comprises a plurality of supporting straps designated generally by the numeral 52. The straps are bowed as at 53, to form arcuate portions adapted to contact with the outer shell of the evaporator. Below the evaporator the straps areprolonged to form extensions 54 which are in perpendicular alignment with the segments above the arcuate portions. The ali ned portions of the straps are drilled above and below the evaporator to receive bolts As shown, these bolts are threaded at both ends to receive nuts 56.. It will, however, be readily appreciated that headed bolts may be used, or any suitable fastening means. The clamping means are rigidly held and prevented from displacement by means of *members 57 and 58. These members comprise strips of iron upset at both ends to form securing flanges 59. The flanges are provided with suitable holes, not shown, to register with bolt 55, headed bolt 60 and screw 61. The stiffening members are secured to the wall of the shroud and the inner wall of the refrigerator by the bolt and screw above described and are connected centrally by bolt 55 and nuts 56 to register with the extensions 54 of the clamping means. Intermediate the flanges 54 and 59 and also in register with the bolt are flanges of the supports 61 whose function will be discussed more in detail.

In assembling. the evaporator is slid into the space defined by the arcuate portions 53 of the straps and thenuts tightened until the evaporator is firmly clamped into position. This construction permits of vertical adjustment of the evaporator as well as the longitudinal adjustment thereof, either or both being readily accomplished by loosening the appropriate nuts, aligning, and tightening.

the nuts again. This feature of universal adjustability of the clamping means permits the evaporator to'be readily and securedly set up in its proper position and further assures its easy withdrawal in case it is to be repaired.

In connection with the clamping means just described, we have provided means for storing extra ice, when desired. To accomplish this, supports 61 are suspended by their flanges from bolt 55 and are securely held by tightening nuts 56. The supports are conformed to the spacing members 57 and 58, as shown at 62, and then bent downwardly and inwardly to form supporting shelves 63. These shelves are so constituted and arranged as to be able to support an ice tray of the type ordinarily used in household refrigerators ofthe mechanical type and which tray or drawer is designated generally reserve shelf and inserting a fresh unit in its place. In addition to acting as a reserve ice supply, the drawer 64 serves as a drip collector for the moisture condensed on the outer surface of the evaporator, thereby keeping the lower portions of the refrigerator from such accumulations. In addition, the ice in the drawer aids in cooling the 7 descending alr.

These features are of distinct value in permitting the full utilization of the refrigerating capacity of the apparatus and its economical maintenance. The extra drawer is positioned somewhat below the level of the bottom of the front wall of the shroud to permit of its easy insertion and withdrawal. I

Yet another clampingmeans is shown in Figs. 7 and 8. In this modification, a plurality of straps, designated generally as 190 and 19d, are welded on to a clamping ring 65 as indicated at 66. The ring is provided with flanged members 67 which are adapted to be drawn together by means of the headed bolt 68 and clamping nut 69. The straps are provided with flanges 21 for securing the apparatus to the top of the refrigerator chamber. While the clamping ring has been shown as having upwardly extending jaws, it will, of course, be readily understood that any desired arrangement may be provided without departing from the spirit and scope of our invention. This arrangement likewise permits of the ready installation and removal of the evaporator when desired, and facilitates its proper alignment.

As intimated before, we overcome the difficulties due to expansion and contraction stresses set up in the metal of the evaporator by suspending the latter'in a plurality of stirru s as shown and described. By the use 0 these novel devices, the evaporator is free to contract and expand without causing any buckling of the metal with its tendency to disrupt the device.

It will now readily be seen that the improved constructions embodying our invention are adapted for use in a wide variety of refrigeratin devices, and are not to be restricted to t e preferred embodiments herein shown, which are given merely by way of example.

We claim:

'1. Suspension means for the evaporating unit of a mechanical refrigerator, comprising, in combination, a plurality of hoops having split portions, suspension straps welded to the hoops, and clamping means adapted to coact with the split portions of the hoops.

2. An evaporator for a refrigerating apparatus comprising inner and outer walls arranged to form a chamber for refrigerant, a refrigerant inlet conduit connection communicating with said chamber through one of said walls, a refrigerant outlet conduit connection communicating with the upper portion of said chamber through the inner wall thereof.

3. An evaporator for a refrigerating apparatus comprising inner and outer walls arranged to form a chamber for refrigerant, a refrigerant inlet conduit connection communicating with said chamber through one of said walls, a refrigerant outlet conduit connected through the inner wall with the upper portion of said chamber and extending downwardly from said inner wall.

4:. An evaporator for a refrigerating apparatus comprising inner and outer walls arranged to form a chamber for refrigerant and a freezing compartment, a refrigerant inlet conduit connection communicating with said chamber through one ofsaid walls, a refrigerant outlet conduit connected through the inner wall with the upper portion of the refrigerant chamber and extending downwardly from said inner wall into the freezing compartment.

In testimony whereof we afiix our signatures.

HARRY R. VAN DEVENTER. J. ALFRED GRIER.

CERTIFICATE OF CORRECTION.

Patent No. 1,888,336. November 22, 1932.

HARRY R. VAN DEVENTER ET AL.

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page i, iine 5, heading to specification, for Serial No. "299,001!" read "229,001"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record' of the'case in the Patent Office. I

Signed and sealed this 17th day of January, A. D. 1933.

- M. J. Moore, (Seal) Acting Commissioner of Patents. 

